SUSE Linux used to be a very KDE-centric distribution. Then Novell came around, bought SUSE and Ximian, and slowely but surely they turned the now-openSUSE distribution into effectively a GNOME-centric distribution with KDE as its sidekick. The openSUSE community, however, doesn't appear to be particularly happy with KDE being a sidekick.

Qt had the advantage of starting to implement its accessibility bridge on Linux at a point where it was already decided to use D-Bus instead of CORBA.

So a system using the deprecated AT-SPI setup works better with GTK based applications, a system using the newer AT-SPI setup will work better with Qt based applications. As written above, this difference will be removed in the near future when Bonobo deprecations is completed.